In the CSMA-CA procedure for IEEE 802.11 (WiFi) communications, a communication device (CD) that experiences a transmission collision delays its access to a medium for retransmitting data by a determined back-off time. The CD can determine that a collision has occurred when the CD performs the CCA and detects the medium is busy, indicating that another transmission occurred at the same time, interfering with the CD transmission. The back-off time is calculated by selecting a random number from a predetermined window size. A Markov Chain analysis of throughput using this formula for calculating the back-off time reveals that the peak throughput can be sustained at about 70% of the overall throughput in normal network conditions (acceptable density of CDs or transmissions). The back-off time, or contention window, is increased based on previous failure of a transmission or according to detection of collisions with other CD transmissions, for example, by doubling the back off time and retransmitting the data using the new back off time. For successive transmission failures, the back off time is successively doubled as long as collisions continue to occur. The doubling stops when the back-off time reaches a maximum back-off time CWmax. An improved procedure for determining the back-off time that results in fewer collisions between CDs and higher overall throughput is favorable for high wireless traffic situations, such as for high density of CDs in an area or high transmission concentration in an area that may cause a large number of collisions in random access transmissions.